Seongnam is a city in Gyeonggi Province, South Korea. Because of its convenient location near Seoul, it is a largely residential city with a population that merges with other residential cities. Its most heavily occupied sector is the Bundang Development Borough, which is home to a huge amount of multi-skyscraper apartment complexes that are also common in other major Korean cities. In addition, the Bundang Borough serves as Seongnam's heart and provides the rest of the city with the Bundang Subway Line, which extends into Seoul.